The invention relates generally to power-driven conveyors and more particularly to modular plastic conveyor belts with on-board electronic communication devices.
Packaging electronic devices for installation in conveyor belts is challenging. Rugged industrial environments require a tough housing material, such as steel. In the food industry, further sanitary requirements may limit the choice to stainless steel. If the electronic devices include communications devices with antennas, the surrounding metallic housing acts as a shield, blocking wireless radio signals to and from the embedded antennas. One solution is to make the housing with a non-metallic portion, such as a plastic cap forming a portion of the housing. But it is difficult to form a reliable seal between the plastic and the metal to protect the electronics from liquid incursion without making a much larger package. And plastic-to-metal seals are not as reliable as hermetic metal-to-metal seals. Furthermore, even if the plastic cap provides a clear line of sight from the embedded antenna to a base antenna, the proximity of the metallic portion of the package to the embedded antenna can still block the signal. Furthermore, embedding the antenna within the package limits the space available for the antenna and, consequently, the range of possible efficient antenna designs.